Microwave oven



FIG. 1 is a perspective front view of a microwave oven showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a perspective front view of FIG. 1, with the door shown in a partially open position.

The details shown in broken lines form no part of the claimed design. 

The ornamental design for a microwave oven, as shown and described. 